<template>
  <div class="star" :class="starType">
    <span v-for="(itemClass,index) in itemClasses" :key="index" :class="itemClass" class="star-item"></span>
  </div>
</template>

<script type="text/ecmascript-6">
  const LENGTH = 5;
  const CLS_ON = 'on';
  const CLS_HALF = 'half';
  const CLS_OFF = 'off';

  export default {
    name: 'star',
    props: {
      size: {
        type: Number
      },
      score: {
        type: Number
      }
    },
    data() {
      return {}
    },
    computed: {
      starType() {
        return 'star-' + this.size;
      },
      itemClasses() {
        let result = [];
        let score = Math.floor(this.score * 2) / 2;
        // 控制是否有半星
        let hasDecimal = score % 1 !== 0;
        // 有几个全星
        let integer = Math.floor(score);
        for (let i = 0; i < integer; i++) {
          result.push(CLS_ON)
        }
        if (hasDecimal) {
          result.push(CLS_HALF)
        }
        while (result.length < LENGTH) {
          result.push(CLS_OFF)
        }
        return result;
      }
    }
  }
</script>

<style lang="scss">
  @import "../../common/stylus/mixin";

  .star {
    font-size: 0;
    .star-item {
      display: inline-block;
      background-repeat: no-repeat;
      &:last-child {
        margin-right: 0;
      }
    }
    &.star-48 {
      .star-item {
        width: 20px;
        height: 20px;
        margin-right: 22px;
        background-size: 20px 20px;
        &.on {
          @include bg-image('./img/star48_on')
        }
        &.half {
          @include bg-image('./img/star48_half')
        }
        &.off {
          @include bg-image('./img/star48_off')
        }
      }
    }
    &.star-36 {
      .star-item {
        width: 15px;
        height: 15px;
        margin-right: 16px;
        background-size: 15px 15px;
        &.on {
          @include bg-image('./img/star36_on')
        }
        &.half {
          @include bg-image('./img/star36_half')
        }
        &.off {
          @include bg-image('./img/star36_off')
        }
      }
    }
    &.star-24 {
      .star-item {
        width: 10px;
        height: 10px;
        margin-right: 3px;
        background-size: 10px 10px;
        &.on {
          @include bg-image('./img/star24_on')
        }
        &.half {
          @include bg-image('./img/star24_half')
        }
        &.off {
          @include bg-image('./img/star24_off')
        }
      }
    }
  }
</style>
